Lighting Fixtures.pdf

7/29/2019 Lighting Fixtures.pdf

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Lighting Fixtures

Recessed Lighting

-Lamp Types

- Incandescent

- Tungsten Halogen

- Fluorescent

- HID (metal halide)

- Rare use of fiber-optics and LED

Parts of a fixture:

http://www.epl.com/fixture_movie.cfm?FixtureID=533


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Recessed Lighting

-Reflectors

-Cutoff

-Glare

-Distribution

-Wet or Dry

Recessed Lighting

-Reflectors

- Trim


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Recessed Lighting

-Performance

- Downlight

Recessed Lighting

-Performance

- Accent


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Recessed Lighting

-Performance

- Accent

Recessed Lighting

-Performance

- Wallwash


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Track

-Track heads vs. Track

-Range of light sources, from

incandescent, halogen, HID to

fluorescent

-Flexibility for temporary setups

-Easily focused and accessorized

-Different optics eg: Wallwash, spot,

gobos, etc

Track


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Track

Mounting of track

-Suspended

-Surface mounted

-Recessed

Track

-Types of track

-Rigid track 1 circuit, 2 circuit, 3 circuit

-Bendable track

-Cable mounted

-Monopoints

-Voltage

-Low voltage

-Line voltage


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Linear Fluorescent Recessed

and Surface mounted

-Diffuse ambient light

-Cost effective and energy efficient

-Direct or direct/indirect

Linear Fluorescent - Pendants

-Indirect, direct, or indirect/direct

-Modular

-Choice of diffusion materials


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Decorative

Decorative

-Contemporary vs. historic

-Generally inefficient diffuse

sources, which serve as accents in

a space

-Look at choice of materials for

diffuser and connection details at

articulations. Also be aware of

canopy or mounting plate

conditions.

-Often companies will customize

these types of fixtures.


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Exterior Floodlights

Exterior Floodlights

-Distribution and beam shape is

key.

-Be aware of ambient light

conditions contrast is critical.

-Look at gasketing will this

leak?

-How is this going to attach to

your building?

-Does this fixture need a

transformer or ballast? Is it line

voltage or low voltage?


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Exterior Ingrade

Lighting the path vs. uplighting a building

-Where is this located?

-Slab

-Gravel

-Foliage

-Driveover?

Exterior

Misc Exterior

-Drive-overs

-Bollards

-Steplights


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Architectural

-Certain fixtures are designed to be

integrated into an architectural detail. As

such, they either lack an optical control

element or have little external

casing/housing.

http://www.grandbrass.com/

CIE Luminaire Types / Distributions


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Candlepower Distribution Curve

Candlepower distribution

curves provides intuitive

information on how a

luminaire will perform

Candela values are used in

calculations to predict light

levels

Asymmetrical Distribution Curve


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Photometry Reports

Plot of candlepower values

Summary of candlepower values

in different planes

Fixture Efficiency

Lumen Summary

Luminance summary

Spacing criteria (SC) or

Spacing/Mounting Height (S/MH)

for uniformity

Coefficient of Utilization TableGuides

Lighting Calculations

Point by point calculations

-Lumen method

-IES files and computer calculations


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Point-by-Point Foot-candle = Candle PowerDistance 2

FC = 2651candelas/ 9ft2

FC = 2651 / 81

FC = 32.7foot-candles


FC = 2651candelas/ 9ft2

FC = 2651 / 81

FC = 32.7foot-candles


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To solve forD, you can:

1. Scale the Drawing, or

2. Use Trigonometry

X2 + Y2 = Z2

32 + 62 = D2

9 + 36 = D2

D = (9 + 36)

D = 6.7


FC = 169 candelas / 6.7ft2

FC = 169 / 44.89

FC = 3.76 foot-candles


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Depreciation factors

Light Loss Factors to Consider

Dirt

Lamp Depreciation

Environment

Ambient Fixture Temperature

Supply Voltage Variation (Low Voltage approx 4%)

Ballast Factor(Fluourescent approx 90%)

Lamp Burnouts (approx 80%)

Lamp Lumen Depreciation (Fluourescent aprox 70%)

Fixture (Luminaire) Dirt Depreciation

Lighting Calculations Lumen method

Calculates the Average Illumination for a room.

Takes into account the room surface reflectance's but

assumes the surfaces are diffuse (not shiny!).

Assumes an empty room (without furniture).

Can also be used to determine the required Quantity of Fixtures

needed for a target light level.

Does not determine light fixture layout or location you must

following manufacturers spacing criteria.


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Lighting Calculations Lumen method

1. You need Room Dimensions and the Fixture Mounting Height.

2. You need to select a Light fixture

3. Determine the rooms Room Cavity Ratio (RCR).

4. Look-up the fixtures Coefficient of Utilization for the RCR.

5. Calculate

Room Reflectance Surfaces with lessreflectance will bounce less

light

Typical Reflectance

Values:

75%-90% White, Off

White, Grey, Light tints

of Blue or Brown 30%-60% Medium

Green, Yellow, Brown,

or Grey

10%-20% Dark Grey,

Medium Blue

5%-10% Dark Blue,

Brown. Dark Green,

and many wood

finishes


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Room Reflectance Typical CommercialValues:

80% Ceiling

50% Wall

20% Floor

Typical Industrial Values:

50% Ceiling

30% Wall

20% Floor

Room Cavity Ratio 5xMHx(L+W)RCR = Room Area

Room Cavity Ratio (aka

RCR) is the volume

between the Fixture and

Height of Calculation

Workplane height is

typically 30-inches

above the floor

A rooms RCR will

always be between 1

and 10


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Room Cavity Ratio 5xMHx(L+W)RCR = Room Area

Example:

Room Width: 12ft

Room Length: 15ft

Ceiling Height: 10ft

RCR = 5(5.5)(12+15)

(12x15)

RCR = 742.5

180

RCR = 4.1

Coefficient of Utilization 5xMHx(L+W)RCR = Room Area

Also known as CU

Defines the percentage of

light output that is expected

from a fixture

The value is determined

by a CU table

For our example of a

RCR =

4.1the CU is in th is

range

For commercial

Reflectance of80/50/20,

the actual CU value is

this.


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Lumen Method Formula

To Calculate Foot-candle level:

To Calculate number of Fixtures:

Lumen Method Formula

FC = Qty of Fixtures x Number of Lamps per Fixture x Lumens per

Lamp x CU

Area of the Room

FC = Total Lumens in the Room x CU

Area of the Room

Qty of Fixtures = FC x Area of the Room

Number of Lamps per Fixture x Lumens per Lamp x CU

Qty of Fixtures = FC x Area of the Room

Total Lumens in the Room x CU

Lumen Method Example

What is the resulting Foot-candle

Level at table height from four

downlights?


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Lighting Calculations Computer

Three main standards of fixture photometric data: IES, Eulumdat and

Dialux ULD data

-IES is the most commonly available and used format in North

America. Programs such as AGI and Lumen Micro and various freesoftware applications from manufacturers use this format.

-Usually available in a file per fixture format or as one download for the

entire fixture range available.

-http://www.lightolier.com/index.jsp?CATREL_ID=2196&CAT_ID=27&B

LK=Y&CAT_NAME=4+1%2F2%22+Aperture&PARREL_ID=2015&A=2

54&B=363&C=365


Typical file format (may be opened as a text file, but needs the .ies

suffix to be used in calculation programs):

I ESNA: LM- 63- 1995

[ TEST] A7053BK

[ TESTLAB] LOL FALL RI VER

[ I SSUEDATE] 8-14- 05

[ MANUFAC] LI GHTOLI ER

[ LUMCAT] A7053BKW

[ LUMI NAI RE] CALCULI TE 4. 5" I NCANDESCENT RECESSED DOWNLI GHT

[ MORE] BLACK FI NI SH TRI M

[ LAMP] 75W A- 19

TI LT=NONE

1 1190 1 11 1 1 1 - 0. 34 0 0

1 1 75

0 5 15 25 35 45 55 65 75 85 90

0

427. 00 422. 00 369. 00 368. 00 200. 00 89. 00 0. 00 0. 00 0. 00 0. 00 0. 00


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Photometric grid False colour rendering

Agi32 calculation software

Documents

Lighting Fixtures.pdf